package com.zjapl.web.util.aes;

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
/** 
 * @author 作者:方武斌    E-mail: fangwb@zjapl.com
 * @version 创建时间：2013-1-14 上午10:51:01 
 * 类说明 
 */
public class AES {
	/**
	* AES加密算法
	*/
	public AES() {
	}
	/** 
	* 加密 
	* @param content 需要加密的内容 
	* @param keyWord  加密密钥 
	* @return byte[]  加密后的字节数组
	*/  
	public static byte[] encrypt(String content, String keyWord) {  
	       try {             
	               KeyGenerator kgen = KeyGenerator.getInstance("AES");
	               SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG" );  
	               secureRandom.setSeed(keyWord.getBytes());  
	               kgen.init(128,secureRandom);  
	               SecretKey secretKey = kgen.generateKey();  
	               byte[] enCodeFormat = secretKey.getEncoded();  
	               SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");  
	               Cipher cipher = Cipher.getInstance("AES");// 创建密码器  
	               byte[] byteContent = content.getBytes("utf-8");  
	               cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化  
	               byte[] result = cipher.doFinal(byteContent);  
	               return result; // 加密  
	       } catch (NoSuchAlgorithmException e) {  
	               e.printStackTrace();  
	       } catch (NoSuchPaddingException e) {  
	               e.printStackTrace();  
	       } catch (InvalidKeyException e) {  
	               e.printStackTrace();  
	       } catch (UnsupportedEncodingException e) {  
	               e.printStackTrace();  
	       } catch (IllegalBlockSizeException e) {  
	               e.printStackTrace();  
	       } catch (BadPaddingException e) {  
	               e.printStackTrace();  
	       }  
	       return null;  
	}
	/**
	* @param content 需要加密的内容
	* @param password 加密密钥
	* @return String  加密后的字符串
	*/
	public static String encrypttoStr(String content, String password){
	return parseByte2HexStr(encrypt(content,password));  
	}
	/**解密 
	* @param content  待解密内容 
	* @param keyWord 解密密钥 
	* @return  byte[]
	*/  
	public static byte[] decrypt(byte[] content, String keyWord) {
	       try {  
	                KeyGenerator kgen = KeyGenerator.getInstance("AES");  
	                 SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG" );  
	                secureRandom.setSeed(keyWord.getBytes());  
	                kgen.init(128,secureRandom);  
	                SecretKey secretKey = kgen.generateKey();  
	                byte[] enCodeFormat = secretKey.getEncoded();  
	                SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");              
	                Cipher cipher = Cipher.getInstance("AES");// 创建密码器  
	               cipher.init(Cipher.DECRYPT_MODE, key);// 初始化  
	               byte[] result = cipher.doFinal(content);  
	               return result; // 加密  
	       } catch (NoSuchAlgorithmException e) {  
	               e.printStackTrace();  
	       } catch (NoSuchPaddingException e) {  
	               e.printStackTrace();  
	       } catch (InvalidKeyException e) {  
	               e.printStackTrace();  
	       } catch (IllegalBlockSizeException e) {  
	               e.printStackTrace();  
	       } catch (BadPaddingException e) {  
	               e.printStackTrace();  
	       }  
	       return null;  
	}
	/**
	* @param content 待解密内容(字符串)
	* @param keyWord 解密密钥
	* @return byte[]
	*/
	public static byte[] decrypt(String content, String keyWord) {
	return decrypt(parseHexStr2Byte(content),keyWord);  
	}
	/**将二进制转换成16进制 
	* @param buf 
	* @return  String
	*/  
	public static String parseByte2HexStr(byte buf[]) {  
	       StringBuffer sb = new StringBuffer();  
	       for (int i = 0; i < buf.length; i++) {  
	               String hex = Integer.toHexString(buf[i] & 0xFF);  
	               if (hex.length() == 1) {  
	                       hex = '0' + hex;  
	               }  
	               sb.append(hex.toUpperCase());  
	       }  
	       return sb.toString();  
	}
	/**将16进制转换为二进制 
	* @param hexStr 
	* @return  byte[]
	*/  
	public static byte[] parseHexStr2Byte(String hexStr) {  
	       if (hexStr.length() < 1)  
	               return null;  
	       byte[] result = new byte[hexStr.length()/2];  
	       for (int i = 0;i< hexStr.length()/2; i++) {  
	               int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16);  
	               int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16);  
	               result[i] = (byte) (high * 16 + low);  
	       }  
	       return result;  
	}  

	/*public static void main(String[] args) {
	String content = "123456";  
	String Key = "http://www.zjapl.com";  
	  
	//加密
	System.out.println("加密前：" + content);
	String encryptResult = encrypttoStr(content, Key);
	System.out.println("加密后：" + encryptResult); 
	//解密  
	byte[] decryptResult = decrypt(encryptResult,Key);  
	System.out.println("解密后：" + new String(decryptResult)); 
	}*/
}
